import { AndroidDeviceData, RetrieveLPResult, RetrieveLPResultCamelCased } from '@telegram-apps/sdk';
/**
 * Returns the underlying signal value updating it each time the signal value changes.
 * @param signal - a signal.
 * @param getServerSnapshot - an optional function returning the signal value snapshot. It is used
 *   only during SSR to provide an initial value of the signal. When not set, defaults to the
 *   signal itself.
 */
export declare function useSignal<T>(signal: {
    (): T;
    sub(fn: VoidFunction): VoidFunction;
}, getServerSnapshot?: () => T): T;
/**
 * @returns Launch parameters from any known source.
 * @param camelCase - should the output be camel-cased.
 * @throws {LaunchParamsRetrieveError} Unable to retrieve launch parameters. They are probably
 * invalid.
 */
export declare function useLaunchParams(camelCase?: false): RetrieveLPResult;
/**
 * @returns Launch parameters from any known source.
 * @param camelCase - should the output be camel-cased.
 * @throws {LaunchParamsRetrieveError} Unable to retrieve launch parameters. They are probably
 * invalid.
 */
export declare function useLaunchParams(camelCase: true): RetrieveLPResultCamelCased;
/**
 * @returns Launch parameters in a raw format from any known source.
 * @throws {LaunchParamsRetrieveError} Unable to retrieve launch parameters. They are probably
 * invalid.
 * @see retrieveRawLaunchParams
 */
export declare function useRawLaunchParams(): string;
/**
 * @returns Raw init data from any known source.
 * @throws {LaunchParamsRetrieveError} Unable to retrieve launch params from any known source.
 */
export declare function useRawInitData(): string | undefined;
/**
 * Retrieves Android device data from the navigator.userAgent.
 * @see https://core.telegram.org/bots/webapps#additional-data-in-user-agent
 */
export declare function useAndroidDeviceData(): AndroidDeviceData;
/**
 * Retrieves Android device data from the specified User Agent.
 * @see https://core.telegram.org/bots/webapps#additional-data-in-user-agent
 * @param userAgent - user agent.
 */
export declare function useAndroidDeviceDataFrom(userAgent: string): AndroidDeviceData;